Field
The present invention relates to a separator for a fuel cell, the fuel cell, and a method of manufacturing the separator.
Related Art
A fuel cell has a stacked structure in which a plurality of unit cells, each of which serves as a power generator, are stacked. Each unit cell includes separators, and the separators divide the unit cell from other adjacent cells. Each separator involves in supply and discharge of fuel gas, oxygen containing gas, and cooling water to/from the unit cell, and is provided with a gasket for sealing passages of the gas and cooling water. The gasket is formed by die-casting rubber-like elastic material. Since the die-casting often involves leaks of the die-casting rubber material from cavities for shaping the gasket, which causes a formation of burrs, the burrs must be addressed somehow. As one approach of addressing the burrs, for example, JP2008-146986A proposes an approach in which an air vent portion is formed in a die at a merging portion of die-casting rubber material, an excessive part of the die-casting rubber material is forced to fill in the air vent portion to collect the burrs in the air vent portion, and the burrs are cut and removed.
Although the approach described above can reduce the formation of burrs at parts other than the air vent portion, the cutting of the burrs at the air vent portion may cause damages to the gasket. Therefore, a burr cutting mechanism with a higher positioning precision is required, and a careful burr cutting work is necessary, resulting in a complicated process as a whole. For this reason, a simple burr handling in the die-casting product made of rubber-like elastic material, such as a gasket, came to be demanded.